Comment on the narrow charmonium state of Belle at 3871.8 MeV as a deuson

TL;DR

This paper suggests that the narrow charmonium state at 3871.8 MeV observed by Belle is likely a deuteron-like meson-meson molecule called a deuson, predicted over a decade ago, with specific quantum numbers and decay modes.

Contribution

It proposes that the observed state is a D D* deuson, providing a meson-meson molecular interpretation consistent with prior predictions.

Findings

The state is likely a D D* deuson with specific spin-parity.

Expected decay mode via D^0 D̄^0 π^0 with ~50 keV width.

Supports molecular interpretation over conventional charmonium.

Abstract

It is pointed out that the narrow charmonium state at 3871.8 MeV reported by the Belle collaboration is likely to be a $D\bar D^*$ deuteronlike meson-meson state called a deuson. It was predicted near the $D\bar D^*$ threshold over 10 years ago. Its spin-parity would be 0-+ or 1++ and an important decay mode should be via $D^0\bar D^{*0}$ to $D^0\bar D^0\pi^0$. Its width to that channel should then be of the order 50 keV. Note: A more detailed update of this unpublished note is in hep-ph/0402237.